A couple of days ago, Brown started limping on his right back leg, and within the last year or so, this wasn't unusual for him after strenuous exercise or rough-housing with Grey. We think he got hurt going up the steps, when Grey, who has the attention of a housefly, ran up the steps and into Brown, knocking him partially off the steps. Anyway, I made an appointment to have him checked out because I'm always concerned about his hips and knees since he's a lab and getting older, and we don't know his history. I even started him on glucosamine almost two years ago just incase. Anyway, he was examined in May during his yearly physical, and the vet said his hips were great. We saw our regular vet at the same clinic today who was impressed with him. She said his hips are excellent, and he's "well-preserved" for seven. He's even at his ideal weight, although losing one or two pounds wouldn't hurt. His coat is glossy, his teeth are immaculate, and his joints are great, despite the knee thing. So she gave him a pretty good exam today and found that he strained his crucuiate ligament and prescribed meds for a few days. I told her how he does limp from time to time after really pushing himself, and she said that it could be a repeated injury. Brown really isn't limping anymore...it's very slight, and he should be back to normal in a few days, but does anyone have advice, especially if this is something that will happen continuously?